Refrigerating apparatus



0a. 25, 1932. Mjw. BAKER 1,883;864'

REFR IGERATI NG APPARATUS Filed Oct. 31. 1929 2 Sheets-Sheet l IN VEN TOR W W W w y rromsyj Oct. 25, 1932. w, BAKER REFRIGERATING APPARATUS Filed Oct. 31. 1929 2 Sheets-Sheet 2 W ILIVENTOR BY W AITORNEYS Patented Oct-'25, 1 932 I UNITED STATES PATENT OFFICE MARSHALL W. BAKER, OF DAYTON, OHIO, ASSIGNOR TO FRIGIDAIRE CORPORATION, 03 DAYTON, OHIO, A CORPORATION OF DELAWARE lnnrnmnna'rme arraaa'rus Application filed October 81, 1929. Serial No. 403,780.

This invention relate-s to refrigerating apparatus and especially to apparatus for returning oil fromthe evaporator to the compressor'of a refrigerating system.

One of the ob ects of the invention is to provide means whereby there is not an excess of oil in the evaporator of the refrigerating system. i

Another object is to prevent liquid refrigerant from returning with the oil and gas.

Another object of the invention is to provide positive means for returning oil above a predetermined level in the evaporator to the compressor.

Another object of the invention is to pro.- vide means for withdrawi a certain portion of the lubricant from th liody of liquid in the evaporator during the idle periods of the refrigerant liquefying unit and to have such oil return with the evaporated refri erant during the operation periods of the re rigern ant liquefying unit.

Further objects and advantages of the present invention will be apparent from the following description, reference bein had to the accompanying drawings, wherein a preferred form of the invention is clearly shown.

In the drawings:

Fig. 1 is a view partly in cross section thru an evaporator illustrating the application of the invention and partly diagrammatic of a system connected to said evaporator.

Fig. 2 is a detailed view of certain elements of the evaporator in Fig. 1 when the evaporated refrigerant is being withdrawn from the evaporator.

Fig. 3 is a top view of Fig. 2.

Fig. 4 is a cross section on lines 44 of Fig. 1.

One of the problems in connection with the refrigerating system is that of the circula-' tion thru the system of the lubricant supplied to the compressor for its necessary lubrication of moving parts. The vaporized refrigerant is generally drawn to the compressor bv suctioncreated by-a pumping action in the compressor and on being compressed is forwarded under pressure to the other elements of the refrigerating system. This process of suction compressing and forsulphur dioxide is used the oil will form a blanket on the top of the liquid refrigerant in the evaporator or expander. If too much oil is drawn from the compressor it may result in the moving parts of the compressor a being damaged for want of sufiicient lubrication. If the oil blanket becomes very thick in the evaporator it decreases the efliciency of the apparatus by taking the place of the liquid refrigerant and furthermore by hindering the suitable rate of evaporation of the liquid refrigerant. Accordingly it is one of the objects of this invention to provide means for returning any excessive oil in the evaporator to the compressor.

It is desired however to prevent any liquid refrigerant from also returning with the oil and causing the frosting over of the conduits between the evaporator and the compressor. This frosting over causes a loss of efiiciency due to the fact that this liquid refrigerant is not being evaporated or vaporized in the evaporator. A more serious. objection from the housewifes point of view is the fact that this frost will melt and cause very undesirable puddles of water on the floor.

Accordingly it is another object of the invention to provide not only means that .would normally prevent the liquid refrigerant from entering the outlet means for the matic the evaporator has been illustrated in an enlarged cross sectional view to illustrate the a plication of the invention in a preferre manner to a preferred type of evaporator. The system in general comprises a single return conduit 10 for the refrigerant gas and oil that isconnected to the crank case of the com ressor 11. The compressor operation of the snap-switch 17 in response to the temperature condition of the evaporator; Th1s snap switch controls the operation of the motor 19 that runs the compressor 11 preferably thru a belt means 20. When the temperature inside the evaporator reaches a predetermined maximum its pressure will operate the bellows'16 that in turn starts up the motor thru the snap switch 17. Upon such starting of the motor and the compressor a suction will be created in the single return conduit 10'and liquid refrigerant will be supplied tothe evaporator. Whfifthe pressure temperature conditions within the evaporator again reach the desired-state the decrease in pressure will operate the bellows 16 to interruptthe circuit to the motor 16'to stop the motive power for the compressor. I Upon this "unit.

stopping of the compressor the liquid refrigerant will stop being supplied to the interior of the evaporator and the body of liquid therein will settle to its proper level.

At the beginning of operation of the system the period of time between starting, of the motor and compressor and'stopping thereof is referred to as the on phase of a cycle of operation of the refrigerant liquefying unit. The'period of time between two successive operating periods or'on phase of the refrigerant liquefying unit is referred to as an of! phase of a cycle of operation of the Thus it is apparent that while the system 'is in operation to producerefrigeration, the refrigerant liquefying unit is cyclically operated and that each cycle thereof includes an on phase and an off base.

Furthermore the system rom the point of compression in the compressor to the entrance of the liquid refrigerant to the evaporator is generally referred to as the high pressure side of the system. The evaporator and its return conduit to the crank case of the compressor is generally referred to as the low pressure side of thesystem.

The evaporator 15 comprises the tank or boiler 21 having a closure or valve plate momber 22 for its cylindrical 0 en end. A supporting member 23 preferably surrounds the open end of the boiler for support thereof and also to receive the fastening means'24 that secures the valve plate to the open end of the boiler. A liquid valve 25 and a suction return valve 26 are preferably supported on the valve plate as shown. The liquid refrigerant enters the liquid port or entrance 27 and passes thru a screen 28 to an opening 29 in the boss 30 projecting from the interior side of the valve plate. A bracket 31 surrounds this opening and supports a needle valve 32 which closes or opens the restricted opening 29 in response to the actions of the float ball 33 on its float ball arm 34 connected to this needle valve. The float ball 33 is adapted to maintain a considerable constant quantity of liquid refrigerant within the'evaporator 15. An outlet port 35-- is also located in the upper portion of the valve plate for the egressof the evaporated refrigerant.

As previously explained oil generally passes from the compressor 11 where it is needed thru the condenser 12 and receiver 13 to the evaporator. Where a refrigerant such as sulphur dioxide is used this oil will form a blanket 36 on the surface of the liquid refrigerant 37 inside the evaporator. This oil blanket will seriously affect the efliciency of the apparatus by preventing the suitable,

evaporation of the liquid, refrigerant especiallyafter the oil passes a certain thickness generally in the neighborhood of three fourths of an inch in household evaporators.

Ac'cordinglylit is desired to maintain this oil blanketbelowa certain thickness generally a maximum of five eighths of which .It is the liquid refrigerant will evaporate in the conduit 10 and cause condensation .and freezingof moisture upon the exterior surface of the conduit 10 w1th its consequent melting and drip inguponthe' floor. Furthermore the liquid refrigerant being evaporated outside the evaporator causes a decrease in efliciency of the apparatus. Accordinglythe invention contemplates special means for not only returning any portion of the oil above a predetermined thickness of the oil blanket but also to prevent any possibility of any liquid 7 refrigerant being returned with the oil.

As disclosed in the drawings a preferred application of the inventioii contemplates one or more walls 40 forming an enclosure41. This enclosure 41 is connected to the outlet port 35 by any suitable means such as the tube 42. The tube also preferably extends downward into the lower portion of the enclosure 41 but leaves aslight space below its lower end 43 as disclosed in Figs. 1 and 2. Preferably projecting upward is a tube or chimney 43 extending from the interior of the enclosure 40. This tube is open at its top to permit the top of the tube 43 fromanvsprizy of theliquid refrigerant. *This skirt is cut away as at 45 so that it will not interfere with the operation of the float ball. In the upper wall of the enclosure 40 is'located an opening 46 for the oil to pass into the enclosure. The

upper wall or this opening 46 at least is located at a predetermined height at which it is desired that the oil should stop. In other words the float ball 33 is calibrated for the desired quantity of liquid refrigerant in the evaporator and the height of the opening 46 controls the thickness of the oil blanket on the surface of the liquid refrigerant. Accordingly the level of the opening 46 may be made as close to the level of the li uid refrigerant as desired.

his oil opening is closed by a closure member 47 which in its preferred simplest form constitutes a spherical ball. To allow the operation of this closure member within definite limits a cage member 48 is placed over the opening and, is secured tb the upper portion of the enclosure 40. This member allows the ball to raise a certain distance above. the opening 46 but also guides it to close the opening under the force of gravitation.

A pivot means 50 is also supplied in the enclosure 40 for the flapper member 51. This flapper member has a counter weight 52 on the side of its pivot opposite the opening 46 and the opening 53 of-the tube 43. TlllS flapper member has preferably a closure member 54 in one end thereofv that will fit over and close the opening 53 in the tube 43. It also has an operating means 55 for operating the closure member 47. In its preferred simple form this is merely a screw threaded through the flapper member and adapted to strike the ball and raise it with a pivoting movement of the counter weight 52. If desired a tiny hole 56 may be put in the cap member 54 to allow draining thru of any oil that chances to splash into the tube 43 and which drains downward onto the cap member 54.

During the idle moments or periods of the refrigerant liquefying apparatus and when liquid in the evaporator has reached its quietest stage, the position of the flapper valve 51 is that illustrated in Fig. 1. The closure member 54 closes the tube 43 under the downward ressure of the counter weight 52 on the ot er side of the pivot 50. The screw 55 has pressed the hall upwardly and this permits all oil or lubricant above the height of the opening 46 to flow into the enclosure 40. The pressure of the gas inside the evaporator will be communicated to a certain extent thru the opening 46 to the bellows 16 for operation of the snap switch 17. If, however, this communication of pressure is not fast enough thru'the openings 46 and 56, the flapper-will momentarily operate to allow the pressures to be equal to the evaporator and the suction conduit 10.

When'the compressor starts operating, suction will be created in the return conduit 10 and the tube 42-andenclosure 40. This will draw down the closure member 54 due to the suction created by the operation of the compressor and the flow of gas instituted thereby thru the-tube 43. Accordingly the lower portion 53 of the tube 43 will be opened and the screw'55 be withdrawn from pressing on the ball 47. Accordingly during the opera I tion of the refrigerant liquefying unit the oil opening will be closed and the opening for the vaporized refrigerant into the closure 40 will be opened. Thispassage of gas into the enclosure 40 and into the tube 42 thru its lower end 43 will carry the oil with it thru the returnconduit 10 to the crank case of the compressor. It will be noted that if any liquid refrigerant has entered into the closure 40 that it will sink to the bottom of the enclosure and have a chance to evaporate before it is drawn up thru the tube 42. When the motor stops and liquid refrigerant stops flowing into the evaporator the liquid inside of the evaporator will settle and the counterweight will again operate to close the lower opening 53 of the tube 43 and will alsofraise the closure member 47 to allow the oil to again pass thru the opening 46. It is obvious p that the shape and arrangement of the various parts is subject to wide variation. Furthermore the invention can be' applied to. withdrawing other undesirable liquids from the evaporator or expander.

the oil blanket to be predetermined and gives an opportunity for the evaporation of liquid: refrigerant before it is drawn into the suction return line.

While the form of embodiment of the invention as herein'disclosed constitutes a preferred form, it is to beunderstood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating system including an evaporator and a refrigerant liquefying unit,

a liquid refrigerant supplied to said evaporator during the operation periods of said refrigerant liquefying unit. a lubricant adapted to accompany said liquid refrigerant to said evaporator and forming with said liquid refrigerant a body=of liquid in said evaporator, outlet means for said lubricant and evaporated refrigerant including walls forming an enclosure, said enclosure having an opening for the evaporated gas and another opening for the lubricant, said open ing for the lubricant being open only during the idle periods of said refrigerant liquefying unit. 1

2. A refrigerating system 'including an evaporator anda refrigerant liquefying unit,

a liquid refrigerant supplied to said evaporator during the operation periods of said 1 refrigerant liquefying unit, a lubricant evaporator and a refrigerant liquefying unit,

adaptedto accompany said liquid refrigerant to said evaporator and forming with said liquid refrigerant a body of liquid in said evaporator, outlet means for said lubricant and evaporated refrigerant including walls forming an enclosure, said enclosure having an opening for the evaporated gas and another opening for the lubricant, a .'closure.

member for each opening, said closure members being alternately operated.

3. A refrigerating system including an a liquid refrigerant s'upp ied to said evaporator during the. operating periods of said .anotherelosure member for said eva orated gas opening, the opening for said lu ricant being .closed' by its closure member during the operation periods of said refrigerantliquefying unit and open durin the'idle periods of said refrigerant lique ying unit.

" *4. A refrigerating system including an evaporator and a refrigerant liquefying'unit, a liquid-refrigerant supplied to said evaporator during the operating periods of said refrigerant liquefying unit, a lubricant adapted to accompany said'liquidrefrigerant vto saidevaporator and forming with said liquid refrigerant a body of liquid in 'said' evaporator, outlet means for said lubricant and evaporated refrigerant including walls forming anenclosure, said enclosure having an opening for the evaporated gas and another opening for the lubricant, a closure member for said lubricant opening, an- 'otherclosure member for said evaporated gas opening, the opening for said lubricant being closed by its closure member during the operation periods of said refrigerant liquefying unit and open during the idle periods of said refrigerant liquefying' unit,

said opening for said evaporated refrigerant being open during the operation periods .of said refrigerant liquefyin'g unit and closed by itslclosure member during the major portion at least of'theidle periods of said re frigerant' liquefying unit.

5. A refrigerating system including an 7 evaporatorand a refrigerant liquefying unit, a liquid refrigerant supplied to said evapora tor during theoperating periods of said refrigerant liquefying unit, alubricant adapted to accompany said liquid refrigerant to said evaporator and forming with said liquid refrigerant a body of liquid in said evaporator, outlet means for said lubricant and evaporated" refrigerant including walls forming an enclosure, said enclosure having an opening for the evaporated gas andanother opening for the lubricant, a closure member for said lubricant opening, another closurev member for said evaporated gas opening, the opening -for said lubricant being closed by its closure member during the operation periods of said refrigerant li'qu'efying unit and open during the idle'periods of said refrigerant liquefying unit,-said opening for said evaporated refrigerant being open during the operation periods of said refrigerant liquefying unit and closed by its closure member during the major portion at least of the idle periods of said refrigerant liquefying unit and unitary operating means for said closure members.

6, An evaporator adapted to contain liquid refrigerant, outlet means for the vaporized refrigerant including walls forming an enclosure, a tube extending from the upper portion of said enclosure, and a skirt surrounding the open end of said tube.

, 7. An evaporator adapted to contain liquid refrigerant, outlet means for the vaporized refrigerant including walls forming an enclosure, a tube extending from the upper portion of said enclosure, and a downwardly extending skirt surrounding the open end of said tu e.

i 8. A refrigerating system including an evaporator and a refrigerant liquefying unit, a liquid refrigerant supplied to said evaporator during the operation periods of said re- I frig'erant liquefying unit, a lubricant adapted to accompany said liquid refrigerant to said evaporator and forming with said liquid re frigerant a body of liquid in said evaporator, means including a check valve for withdrawing a portion of said lubricant from said body of liquid in said evaporator, said means also including a pivoted weight member for opening the check valve only during the idle periods of. said refrigerant liquefying unit, and

means associated with said pivoted Weight member for rendering said member ineii'ery tive during the operating periods of said refrigerant liquefying unit.

9. A refrigerating system employing a refrigerant and a lubricant in which the lubricant and refrigerant separate by gravity, of

an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a portion of the lubricant being delivered from the means to the evaporator with the refrigerant; a single path of flow-for conducting gaseous refrigerant andlub-ricant from the evaporaand actuated in response to each cycle due to the cyclical operation of the system for controlling s aid valve means.

10. A refrigerating system employing a refrigerant and a lubricant in which the lubricant and refrigerant separate by gravity, of an -evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a portion of the lubricant being delivered from the means to the evaporator with the refrigerant; 'a

single path of flow for conducting gaseous refrigerant and lubricant from the evaporator to said first named means, a valve in said single path of flow for controlling the flow of excess lubricant from the evaporator to the first mentioned means; means for starting and stopping said first mentioned means; and

means-in said single pathof flow and actuated in response to each cycle due to the cycl1c al operation of the system for controlhng sa d valve. v

11. A refrigerating system employing a refrigerant and a. lubricant in which the lubri-' cant and refrigerant. separate by gravity, of

an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator,- a portion of the lubricant being delivered from the means to the evaporator with the refrigerant; a

single path of flow for conducting gaseous refrigerant and lubricant from the evaporator to said first named means, a trap in said single path of flow from the evaporator, and means in said single path of flow actuated in re sponse to'pressure for delivering excess lubricant from the evaporator to said trap.

12. A refrigerating system employing a refrigerant and a lubricant in which the lubricant and refrigerant separate by gravity, of

an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a portion of the lubricant being delivered from the means to the evaporator with the refrigerant; a single path of flow for conducting gaseous refrigerant and lubricant from the evaporator to said first named means, a trap in said single path of flow from the evaporator, and means in said single path of flow actuated in response to each cycle of said first named means for delivering excess lubricant from the evaporator to said trap.

13. A refrigerating system employing a refrigerant and a. lubricant in which the lubricant and refrigerant separate by gravity, of an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a portion ofthe lubricant being delivered from the means to the evaporator with the refrigerant; a single path of flow for conducting gaseous refrigerant and lubricant from the evaporator to the refrigerant supplying means,

means for starting and stopping said first mentioned means; means for preventing .the

liquid from rising above a certain level in the evaporator; and means disposed in said single path of flow and actuated in response .to the cyclical operation of the system for causing the flow of excess lubricant from the evapo ratorto the first mentioned means during one part only of each cycle.

14. A refrigerating system employin a refrigerant and a lubricant in which the lubricant and refrigerant separate by gravity, of an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, 'a-portion of the lubricant being delivered from the means to the evaporator with the refrigerant; asingle path of flow for conducting gaseous refrigerant and lubricant from the evapora tor to the refrigerant supplying means, means for starting and stopping said first mentioned means; means for preventing the liquid from rising above a certain level in the evaporator;

and means disposed in said single path of flow and actuated in response to the cyclical operation .of the system for causing the flow of excess lubricant from the evaporator to the first mentioned means during the first part only of each cycle.

1 5. A rfefrigerating system including an evaporator and a refrigerant liquefying unit, a liquid refri erant supplied to said evaporator during t e operating periods of said refrigerant liquefying unit, a lubricant adapted to accompany said liquid refrigerant evaporator, and means engaging said first named means and actuated in response to operations of said refrigerant "liquefying unit for closing said first named means.

16. A refrigerating system employing a refrigerant and a lubricant in which the lubricant and refrigerant separate by gravity, of an evaporator; means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a

ortion of the lubricant being delivered om the means to the evaporator with the refrigerant; a single path of flow for conducting gaseous refrigerant and lubricant from the evaporator to, said first named means, a trap in said single path of flow from the evaporator, and a valve in said single path of flow actuated in response to conditions in the evaporator for deliveringexcess lubricant from the evaporator to said trap.

17. A refrigerating system employing a refrigerant and a lubricant in which the lubricant and refrigerant separate by avity, of an evaporator; means for supp ying liquid refrigerant to and for withdrawing gaseous refrigerant from the evaporator, a

portion of the lubricant being delivered from the means to the evaporator with the refrigerant; asingle path of flow for conducting gaseous refrlgerant and lubricant from the evaporator to said first named means, a trap in said single path of flow from the evaporator, and a valve in said single path of flow actuatedfin response to pressure in the evaporator for delivering excess lubricant" from the evaporator to said trap.

In testimony whereof I hereto afiix my signature.

' MARSHALL W. BAKER. 

